Tworzenie Tablicy 2D z uzyciem petli zagniezdzonej 'for"

Question

const numbers = [];
const columns = 4;
const rows = 5;

for (let i = 1; i < rows; i++) {
     for (let j = 1; j < columns; j++) {
     numbers.push([i][j]);
      console.log(numbers);
     }
  }

 

Comments

Fajne, ale w czym jest problem?

---

Mam jakis blad w tym kodzie. powinno wyswietlic 

[
  [ 1, 2, 3, 4 ],
  [ 5, 6, 7, 8 ],
  [ 9, 10, 11, 12 ],
  [ 13, 14, 15, 16 ],
  [ 17, 18, 19, 20 ]
]

Answer 1

[ edit ]

const columns = 4;
const rows = 5;
let count = 0;
let numbers = new Array(rows);
 
for (let i = 0; i < rows; i++) {
  numbers[i] = new Array(columns);
  for (let j = 0; j < columns; j++) {
    numbers[i][j] = ++count;
  }
}


for (let i = 0; i < rows; i++) {
    console.log(numbers[i]);
}

console.warn(numbers);

lub

const columns = 4;
const rows = 5;
let numbers = new Array(rows);
 
for (let i = 0, count = 1; i < rows; i++) {
  numbers[i] = new Array(columns);
  for (let j = 0; j < columns; j++, ++count) {
    numbers[i][j] = count;
    if (count % 4 == 0) console.log(numbers[i]);
  }
}

console.warn(numbers);

lub

const columns = 4;
const rows = 5;
let numbers = Array.from(Array(rows), () => new Array(columns));
 
for (let i = 0, count = 1; i < rows; i++) {
  for (let j = 0; j < columns; j++, ++count) {
    numbers[i][j] = count;
    if (count % columns == 0) console.log(numbers[i]);
  }
}

lub

const Array2D = (row, col, count) => Array.apply(null, new Array(row)).map(() => {return Array.apply(null, new Array(col)).map(() => { return count++ })})
console.log(JSON.stringify(Array2D(rows,columns,1)));

---------------------------------------------------------------------------------------------------------------

O to chodzi?

const numbers = [];
const columns = 4;
const rows = 5;
 
for (let i = 1; i < rows; i++) {
     for (let j = 1; j < columns; j++) {
     numbers.push([i,j]);
      console.log(numbers);
     }
  }

console.log(numbers[0], numbers[4]);

czy ... ?

const columns = 4;
const rows = 5;
let numbers = new Array(rows);

for (let i = 0; i < rows; i++) {
  numbers[i] = new Array(columns);
  for (let j = 0; j < columns; j++) {
    numbers[i][j] = j;
    console.log(`[${i}][${j}]=${numbers[i][j]}`);
  }
}

console.warn(numbers[1][3], numbers[3][1])
console.log(numbers);

czy ... ?

const columns = 4;
const rows = 5;
let numbers = Array.from(Array(rows), () => new Array(columns));

for (let i = 0; i < rows; i++) {
  for (let j = 0; j < columns; j++) {
    numbers[i][j] = j;
    console.log(`[${i}][${j}]=${numbers[i][j]}`);
  }
}

console.warn(numbers[1][3], numbers[3][1])
console.log(numbers);

czy ... ?

const columns = 4;
const rows = 5;
let numbers = Array.from(Array(rows), () => new Array(columns));

for (let i = 0; i < rows; i++) {
  for (let j = 0; j < columns; j++) {
    numbers[i][j] = [i,j];
    console.log(`[${i}][${j}]=${numbers[i][j]}`);
  }
}

console.warn(numbers[1][3], numbers[3][1])
console.log(numbers);

czy ... ?

const columns = 4;
const rows = 5;
let numbers = Array(rows).fill().map(() => Array(columns));

for (let i = 0; i < rows; i++) {
  for (let j = 0; j < columns; j++) {
    numbers[i][j] = [i,j];
    console.log(`[${i}][${j}]=${numbers[i][j]}`);
  }
}

console.warn(numbers[1][3], numbers[3][1])
console.log(numbers);

 

Comments

Woow, jestem pod wrazeniem. Tak dziala, dziekuje!
Wiele przede mna, zeby moc kodowac na takim poziomie. Czapki z glow!